U.S. Patent Application Publication No. 2009/0112386 (hereinafter referred to as “US 2009/0112386 A1”) discloses a regenerative control process for an electric motor on an electric vehicle while the electric vehicle is driving on a downhill road. More specifically, US 2009/0112386 A1 has the task of operating the electric motor in a regenerative mode while the electric vehicle is driving on a downhill road, in order to cause the vehicle to generate an acceleration suitable for the gradient of the road surface while at the same time minimizing the influences of disturbance factors (see Abstract and paragraph [0007]). In order to carry out the task, according to US 2009/0112386 A1, the electric vehicle has a device 25 for determining, depending on the gradient of the road surface, a target acceleration of the vehicle 1 if the operational states of an accelerator pedal and a brake pedal of the vehicle 1 are an OFF state when the vehicle 1 is driving on a downhill road, a device 26 for determining a correction quantity ΔTrd of a regenerative torque for bringing the actual acceleration of the vehicle 1 close to the target acceleration, a device 21 for determining a basic target torque Trs of an electric motor 2 , which becomes a regenerative torque at the time the operational state of the accelerator pedal is the OFF state, depending on the operational state of the accelerator pedal, and a device 27 for determining a target torque Trc by correcting the basic target torque Trs with at least the correction quantity ΔTrd, wherein the output torque of the electric motor 2 is controlled depending on the target torque Trc (see Abstract).
Electric vehicles include an electric vehicle that is capable of driving forward in a plurality of modes, or stated otherwise, an electric vehicle having a plurality of forward driving ranges {International Publication No. 2010/110098 (hereinafter referred to as “WO 2010/110098 A1”)}. WO 2010/110098 A1 shows a D position and a B position as corresponding to forward driving positions among the shift positions of a shift lever 32 (see FIG. 2). The D position corresponds to a D range which is a forward driving range for transmitting the drive force for moving the vehicle forward to the drive wheels, whereas the B position corresponds to a decelerated forward driving range (engine braking range) for generating an engine braking effect to decelerate the drive wheels by causing the electric motor to generate a regenerative torque, for example, in the D range (see paragraphs [0049] and [0050]).